The present invention relates to a dual voltage electrical system for a vehicle.
Future agricultural and industrial tractors are expected to use higher power electrical auxiliaries to supplement or replace mechanical and hydraulic auxiliaries currently used. For example: electric power steering systems, electric air conditioners, and high voltage/high power xenon lighting systems are just a few of the higher power electrical auxiliaries under evaluation. These systems use higher power than the majority of electrical auxiliaries now in use, and could be implemented more economically and efficiently if they operated at higher voltages (and correspondingly lower currents). To this end, 42 volt automotive electrical components are under development, and in the near future, even higher voltage DC busses will likely be developed.
Since the battery, starter motor, and many low power electrical auxiliaries still require electrical power at the battery voltage, some efficient, inexpensive means to provide electrical power to both a high voltage bus and the lower voltage battery is required. Separate high and low voltage generator/alternators could be used. Separate, high and low voltage windings on the generator/alternator are also known. DC—DC converters to convert power at one voltage level to another are well known. All of these alternatives are expensive.